1. Field
Radon is a cancer causing radioactive gas fluid that has been found in homes all over the United States. Radon typically moves up through the ground to the air above and into a building through cracks and other holes in the floor. You cannot see, smell or taste radon.
Sub-slab depressurization is the most common radon mitigation technique which requires several installation steps.
The radon mitigation system is a continuous piping system beginning under a house concrete basement slab, and terminating outside and above the house.
An inline radon fan is installed in the piping system to draw the radon laced air from under the basement concrete slab to the outside and above the house.
The radon-laced air is pulled from under the basement concrete floor slab by the radon fan and pushed up the exhaust pipe and dispersed harmlessly into the atmosphere.
The radon-laced air is at earth temperature of about 50 degrees Fahrenheit with a high percent of moisture content. This produces air with high humidity content being vented through the radon mitigation system. Radon mitigation protocol requires that radon mitigation systems be operational continuously. The radon mitigation system continues to operate during warm periods of the year and winter freezing periods of the year. During warmer periods, the humid air will turn to condensate and fall back into the radon fan in the form of water which causes damage to the radon fan.
Freezing temperatures in the atmosphere during the winter causes condensate to turn to ice in the radon mitigation system exhaust pipe. As more moist air is blown into the exhaust pipe, ice continues to build and restrict air movement in the upper portion of the exhaust pipe. as the exhaust pipe becomes blocked with ice, the radon mitigation system becomes inoperative. During the warmer periods the ice breaks apart from the exhaust pipe and falls into the radon fan, causing fan damage. It is common for winter nights to freeze and winter days to thaw, resulting in many freeze-thaw cycles during a winter season.
Adding to the ice build-up problem is the birds and animals and debris screen-cap, which often installed at the top end of the exhaust pipe where the humid air is exposed to the freezing temperature of the atmosphere. The screen-cap, installed at the top of the exhaust pipe is directly exposed to freezing temperatures, thus the screen compounds the ice build-up problem as it catches moisture from the air passing through the screen and increases ice build-up. The ice will partially melt, and pieces will break off and drop down into the radon fan, causing damage. The damage to the radon fan from falling ice is a health and economic problem because when the radon fan is not operating, radon is not being removed from the house.
Therefore, for the health and welfare of building occupants it would desirable to provide a means to correct these issues.
2. Prior Art
Currently a radon fan can be somewhat protected from returning water with a condensate bypass apparatus U.S. Pat. No. 6,527,005 issued to Weaver, Mar. 4, 2003. However U.S. Pat. No. 6,527,005 does not provide a means to eliminate the birds and animals screen at the exit point of the exhaust pipe which contributes to undesirable ice build-up. U.S. Pat. No. 6,527,005 does not provide a means to stop ice, birds and animals, debris or rain water from falling into the radon fan. U.S. Pat. No. 6,527,005 does not provide a means for an access port to allow cleaning, inspections or maintenance or a closure device, such as a closure plug, for its access port. U.S. Pat. No. 6,527,005 does not provide a means for an angled shaped housing. U.S. Pat. No. 6,527,005 claim 1, limits the condensate trap to a conically shaped sloping outer surface configuration.
U.S. Pat. No. 6,527,005 states in claim 4 that an exhaust fan apparatus comprising a housing having an exhaust port.
U.S. Pat. No. 6,527,005 states in claim 4 that the exhaust conduit is coupled to said exhaust port.
U.S. Pat. No. 6,527,005 states in claim 4 that a condensate trap located within said exhaust conduit. U.S. Pat. No. 6,527,005 claim number 5 states that the condensate trap is integral with said housing of said exhaust fan apparatus.
Utility patent application Ser. No. 13/068,620 by Bailey (self) May 16, 2011
Application No. 1306820, does not address the issue of the screen, gutter and trough creating air resistance that reduces the amount of air passing through the separator housing.
Application No. 1306820, does not include observation windows within the cap.
Application No. 1306820 does not include observation windows on the sides of the separator housing.
Application No. 1306820 does not include non-mechanical air flow indicators within the separator housing.
Application No. 1306820 does not include mechanical air flow indicators within the separator housing.
Application No. 1306820 does not include an enlarger air passage bulge area within the separator housing to address air resistance.
Application No. 1306820 does not prevent rain water from entering the radon mitigation system.
Application No. 1306820 does not address the issue of moist air originating from the damp sub-soil freezing on the metal surface of the birds and animals screen.
Application No. 1306820 does not include a screen support and gutter floor combined as one and additionally combined as one with the separator housing wall, making the gutter floor, screen support and separator housing to be one unit.
Traditionally steel mesh screen has been installed at the end of the exhaust pipe to keep birds and animals from entering the exhaust pipe. Several problems arise when using a metal screen mesh.
The first problem is that the screen will cause air passage restrictions because of the blockage of air, which can reduce the efficiency of an active mitigation system's fan.
The second problem is the location of the steel screen at the top of the exhaust pipe, where the freezing winter temperatures has a direct freezing effect on the metal wire of the screen causing it to be frozen.
The radon laced air being drawn from under the building concrete slab is often 100% humidity, this means that on some days as much as one gallon of water passes through the mitigation exhaust pipe and through the metal screen. As the humid air comes in contact with the frozen metal screen, ice begins to build up and can choke off the air passage completely. This can cause the active radon mitigation system to have unnecessary strain or shut down, causing harm to the fan and putting the building occupants at a health risk.
The same problems can exist in a passive radon mitigation system even though there is no fan in a passive radon mitigation system.
The third problem with the traditional metal screen at the top of the exhaust pipe is that rain water is allowed to enter the exhaust pipe, possibly causing damage to the radon mitigation fan. Fan manufactures recommend that water not be allow within the fan housing.